EUVD-2025-17341CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Lifecycle Timeline
3Description
A use of externally-controlled format string vulnerability has been reported to affect Qsync Central. If exploited, the vulnerability could allow remote attackers who have gained user access to obtain secret data or modify memory. We have already fixed the vulnerability in the following version: Qsync Central 4.5.0.6 ( 2025/03/20 ) and later
Analysis
Format string vulnerability in QNAP Qsync Central that allows authenticated remote attackers to read sensitive data or modify memory without user interaction. The vulnerability affects all versions prior to Qsync Central 4.5.0.6 (released March 20, 2025), with a CVSS score of 8.1 indicating high severity. While no public exploit or KEV status is currently documented, the low attack complexity and requirement for only low-privilege user access make this a significant risk for organizations running vulnerable versions.
Technical Context
The vulnerability stems from CWE-134 (Use of Externally-Controlled Format String), where user-controlled input is passed directly to format string functions without proper validation. In the context of Qsync Central, this likely occurs in logging, error handling, or network protocol parsing functions where attacker-supplied data reaches printf-family functions. The format string attack allows an attacker to read arbitrary memory locations (information disclosure) or write to memory addresses to modify program flow or data. Qsync Central is QNAP's cloud synchronization and file management service, typically running on NAS appliances and servers as a backend service component.
Affected Products
QNAP Qsync Central (All versions prior to 4.5.0.6)
Remediation
Upgrade to Qsync Central version 4.5.0.6 or later immediately; priority: Critical Access Control: Restrict Qsync Central network access via firewall rules; limit exposure to trusted internal networks only. Implement IP whitelisting for API/service endpoints if accessible remotely.; priority: High Authentication: Enforce strong authentication (multi-factor authentication if available) for Qsync Central user accounts to raise the privilege barrier (currently requires only low-privilege authenticated access).; priority: High Monitoring: Monitor Qsync Central logs for unusual format string sequences (%x, %n, %s) in input parameters, API calls, or protocol messages; monitor for unexpected memory access patterns.; priority: Medium
Priority Score
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External POC / Exploit Code
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